<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  标题标签
  <h1>标题标签</h1>
  <h1>标题一共六级选，</h1>
  <h2>文字加粗一行显。</h2>
  <h3>由大到小依次减，</h3>
  <h4>从重到轻随之变。</h4>
  <h5>语法规范书写后，</h5>
  <h6>具体效果刷新见。</h6>
  
</body>
</html>